Source: ORNL | Release | May 4, 2020
In the fight against the COVID-19 pandemic, it’s a race against the clock not only to find a vaccine but also to supply healthcare workers with life-saving equipment such as face shields, masks and test kits.
Researchers at the Department of Energy’s Manufacturing Demonstration Facility and Carbon Fiber Technology Facility at Oak Ridge National Laboratory are using their materials science, fiber production and additive manufacturing expertise and capabilities to produce tooling such as custom molds for injection molding to provide U.S. industry with the necessary resources to mass produce healthcare supplies in record time.
It’s what Lonnie Love, lead scientist for ORNL’s COVID-related advanced manufacturing initiatives, describes as “catalyzing industry.”
In partnership with the U.S. Department of Defense Industrial Base Analysis and Sustainment Program (IBAS) from the Office of Industrial Policy and the US Department of Health and Human Services, ORNL has mobilized advanced manufacturing researchers at the MDF to develop tooling such as molds that will enable the production of face masks, shields and test collection tubes in quantities estimated from hundreds of thousands to millions. These efforts are at the heart of a new collaboration between DOE and DOD called the America’s Cutting Edge (ACE) program, a national initiative for machine tools technology development and advancement.
“ACE is intended to help the United States recover the technical and manufacturing leadership position and enable our ability to design and make the machine tools required to produce so many of the products that are used in modern society,” said Adele Ratcliff, director of the IBAS program. “We are proud that this partnership was able to pivot its formidable capabilities toward helping relieve the COVID-19 pandemic. Efforts like prototyping tooling to enable industry to be more responsive to economic opportunities and when national security issues arise are central to ACE’s continuing mission.”
According to Love, face shields can be 3D printed but the only way to achieve production volume is through injection molding. “To do injection molding, you need tooling,” Love said. “We’re creating tools in days instead of months. Our efforts make it possible for industry to scale up production.”
Face shield production
Healthcare workers depend on face shields to protect the entire face from hazards such as infectious diseases like COVID-19. A method commonly used to manufacture face shields is injection molding, which works by filling a metal mold with molten plastics to produce large volumes of shields.
At the MDF, researchers worked with Uday Vaidya — ORNL/University of Tennessee Governor’s Chair in advanced composites manufacturing and chief technology officer for the Institute for Advanced Composites and Manufacturing Innovation — to design molds for the mass production of face shields. Working with industry partner DeRoyal Industries, a global manufacturer of medical supplies headquartered in East Tennessee, Vaidya and team produced a mold for use in making the plastic band that fits to the head and holds the shield in place.
“We needed a mold that could be used to exponentially increase the production of face shields, and we didn’t have the time to research and determine the best way to do this on our own,” said DeRoyal Chief Executive Officer Brian DeBusk. “Working with ORNL, we were able to find an immediate solution.”
ORNL’s research team designed, printed and machined a mold ready for industry production within three days.
“We’re driving unparalleled speed to market for important health science materials desperately needed during this crisis,” Vaidya said. “Our team of internationally-recognized academic and business leaders, scientists and students have the flexibility, full support and forward-thinking leadership to remove typical barriers and catalyze the rapid innovation that will help millions of people.”
DeRoyal is using the ORNL-made molds on their injection molding machines.
“We’re making 30,000 shields per day on a single shift working six days per week and using a manual process,” DeBusk said. “However, we’re in the process of automating that process to make them faster and less expensive.”
DeBusk said these shields will be used in thousands of medical facilities throughout the U.S.
Millions of masks
In addition to face shields, ORNL is developing a reusable face mask prototype that DeRoyal is looking to deploy. Vaidya designed the tooling for the prototype and ORNL collaborated with heavy equipment manufacturer John Deere on the initial mold design.
“The strength of collaboration and the willingness to work together towards purposeful innovation is a rewarding and positive outcome during challenging times like this,” said Pushpa Manukonda, director of the John Deere Technology Innovation Center.
The mask is made of five parts and includes a retention ring band, a hard outer shell, filter material, a softer inner shell and an inner retention ring. Rectangular holes can be drilled into the outer mask to add straps.
“Uday’s tooling is enabling us to use metal additive manufacturing to rapidly produce injection molding dies for reusable masks,” Love said. “With five sets of tools, industry can potentially make 300,000 reusable masks per week.”
Decontamination testing is also being performed at ORNL through internal heating experiments in accordance with Federal Drug Administration guidelines.
DeRoyal, in turn, is working with another company to do final assembly work on the mask, DeBusk said. After assembly, DeRoyal will handle distribution of the masks throughout the U.S.
According to Love, the masks can be used hundreds of times by replacing the filter layer made of N95 material. “We worked out the production process for the N95 material too,” Love said. “And, we consulted with the expert, Dr. Peter Tsai, the inventor.”
Filter material breakthrough
At DOE’s CFTF at ORNL, researchers were presented with the challenge of how to produce filtration material for masks on existing equipment typically used to mass produce precursor material for carbon fiber production.
Funded by DOE’s Advanced Manufacturing Office, CFTF Director Merlin Theodore turned to the precursor line’s melt blowing capability for the answer. The N95 mask is made of two plies of melt-blown polypropylene, or PP, a non-woven material that is permanently electrostatically charged with millions of microfibers layered on top of each other. The filter is capable of removing more than 95 percent of submicron particles found in viruses like COVID-19.
“CFTF researchers have developed critical time- and cost-saving parameters to help facilities across the country rapidly start producing N95 filter material,” said Daniel R Simmons, assistant secretary, DOE’s Office of Energy Efficiency and Renewable Energy. “As America works together in the face of COVID-19, resourceful and innovative approaches like these are allowing manufacturers to pivot operations quickly in response to our communities’ needs.”
Melt blowing is a nonwoven process that makes microfibers into a fabric by scattering a polymer resin at a high air velocity. Randomly deposited fibers form a sheet of material applicable for filtration.
“We have the capability to melt blow PP, but we didn’t have the capability to charge the fibers,” Theodore said. “The charge is what’s needed to enhance the filter efficiency.”
That’s where Tsai’s knowledge was critical to the CFTF’s COVID-19 research. A retired University of Tennessee researcher, Tsai invented electrostatic charging, a process in which permanent charges are embedded into a fiber to enhance filter efficiency by electrostatic attraction. Tsai was consulted on how a charging capability could be integrated into the melt blowing line at the CFTF.
Tsai worked with the CFTF team to develop an inline charging technology for the melt blowing line and coordinated with staff at the MDF on material blending. Materials were mixed using the reservoir that normally holds polymers for 3D printing on the Big Area Additive Manufacturing (BAAM) machine at MDF.
“We’ve been successful in melt blowing PP continuously on a belt,” Theodore said. “And, we’ve translated it through an electrostatic charging system to make the filter material.”
Researchers across multiple disciplines at ORNL in materials science, characterization and systems and electrical engineering collaborated to adjust the speed and feed of the material to achieve the optimum production target of 65 grams of material per minute with a fabric weight of 30 grams per meter squared.
“In just one week, we’ve produced a material that meets N95 requirements,” Theodore said.
“We’re also working with Cummins (an engine and power generation manufacturer), which has melt blowing capability presently used for other filter applications, in an effort to enable commercial production of the N95 filter material.”
The Cummins technology used in air, fuel and lube filtration is typically found in heavy-duty diesel engines to prevent long-term engine wear but can also be used in N95 respirator masks.
“Cummins is re-evaluating its supply base and manufacturing capabilities to identify how to support healthcare professionals who rely on critical personal protective equipment to do their jobs,” said Amy Davis, vice president of Cummins filtration.
The CFTF team has met speed requirements for production scale-up so the material can ultimately be supplied to companies like DeRoyal for distribution. ORNL will work with industry on production and DeRoyal is testing the material for use in masks and has placed an initial order.
Test tubes, too
As President Trump announced in a recent COVID-19 briefing, ORNL has also been tasked by the Department of Health and Human Services to develop injection molding tools for the mass production of plastic tubes for COVID-19 test kits. The kits include a swab, saline solution, and the plastic tube to enclose the swab during transport.
“The US goal is to ramp up production to enable one test per person per month, which is 330 million test kits per month,” Love said. “If we created a mold that’s designed to make 36 test tubes in a batch every 10 seconds, and the injection molding machine ran for three shifts, manufacturers could make 300,000 tubes per day. With multiple machines working around the clock, you could achieve the 330 million goal.”
Love said test kit production is limited to one million per week but is rapidly scaling up to 10 million per week, which matches testing capacity.
“As testing capacity grows, so will the need to grow the test kits,” he said. “We are in a race to rapidly solve manufacturing problems currently facing the healthcare system. Every industry we talk to wants to help. Our role is to provide them the tools they need to be successful.”
ORNL scientists are designing a mold prototype made of polymer, which Lawrence Livermore National Laboratory will print and deliver to a nearby industry partner for evaluation. After industry testing, ORNL will use additive manufacturing and machine tooling to produce a metal mold from the prototype that can be used to make millions of parts.
“ORNL’s additive design experts and state-of-the-art equipment make this quick turnaround possible,” Love said. “It would take months to manufacture this tooling in the traditional way, but our researchers are doing it in days.”
The final step, Love said, is to confirm that the mold works so it can be replicated quickly and enable the mass production of collection tubes. Collection tube manufacturing efforts are conducted in coordination with the U.S. Department of Health and Human Services and funded in part by the DOE Office of Science through the National Virtual Biotechnology Laboratory, a consortium of DOE national laboratories focused on response to COVID-19, with funding provided by the Coronavirus CARES Act.
Ventilators and more
ORNL is also researching how to reverse engineer ventilators to 3D print tooling so companies can mass produce them and investigating how to assist with drug delivery and automation.
“We’ve got engineers working at home, across the ORNL campus and at the MDF, collaborating on how we can help industry get the jumpstart they need to meet this unprecedented demand,” Love said. “This refocusing of industry is very similar to World War II efforts. This time, rather than winning a war, we are defeating a pandemic. Timelines are measured in days and weeks rather than months and years.”
It’s a challenge ORNL is historically well suited to meet. The lab was born in the race to bring an end to the last world war, quickly assembling the nation’s top minds and building capabilities for a single purpose. ORNL’s mission of evolving to respond to national priorities continues today.
“We’re here to serve the nation, to find solutions and to deliver technology for the betterment of the U.S.,” Love said. “This is a historical moment in time and ORNL is once again answering the call for America.”
UT-Battelle manages ORNL for DOE’s Office of Science. The Office of Science is the single largest supporter of basic research in the physical sciences in the United States and is working to address some of the most pressing challenges of our time. For more information, please visit https://energy.gov/science/.